Switch for electric circuits



Oct. 31, 1933. w c CARTER 1,933,046

SWITCH FOR ELECTRIC CIRCUITS Filed April 29, 1929 H 7' TOR/v6 a Patented Oct. 31, 1933 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to electric switches, and particularly, automatically-operating switches for intermittently opening and closing an energizing circuit. One object of the invention is to provide a reliable switchor circuit interrupter, of simple design and inexpensive construction, for controlling the energizing circuit of an electricallyoperated pump.

Another object is to provide an automaticallyoperating switch for intermittently opening and closing an energizing circuit, that comprises a plurality of contacts arranged at each side of the gap in the energizing circuit, and a bridge 3 piece that co-acts with said contacts in such a manner as to normally provide a plurality of paths for the electric current, thereby producing a switch that is reliable in operation, due to the fact that there is little liability of dirt or other foreign matter collecting between the bridge piece and all of the contacts of the switch, and thus preventing the switch from functioningproperly to carry-the current across the gap. c

Another object is to provide a switch of the kind above described, in which the bridge piece and the sets of contacts with which it co-operates,:are so constructed and arranged that they are capableof moving relatively to each other in such a manner as to either shake off or dislodge any foreign particles'on the contacts or bridge piece, or cause the bridge piece to bear upon at least two contacts arranged at opposite sides of the gap in the circuit, in the v event the relative movement between the bridge piece and contacts fails to dislodge foreign particles.

And still another object is to provide an automatically-operating switch for intermittently opening and closing an energizing circuit, that comprises a revoluble bridge piece that co-acts with two sets of contacts, one of which sets is mounted on a stationary supporting member and the other set being mounted on a shiftable or m0vab le member whose position will change, in the event a particle of foreign matter collects between one of the contacts thereon and saidbridge piece, thereby insuring the bridge piece engaging at least one of the movable contacts and at least one of the stationary contacts, and thus performing the function for which said bridge piece is designed.

Figure 1 is a horizontal sectional view of a switch constructed in accordance with my invention.

Figure 2 is a side elevational view of, said switch, illustrating how the bridge piece can rock or tilt-on the part on which it is mounted in the event a particle of dirt, sand or other foreign matter becomes deposited between said bridge piece and one of the contacts of the stationary set of contacts; and

Figure 3 is a side elevational view of said switch, showing how the shiftable member which carries the movable set of contacts can change its position in the event dirt or other foreign matter becomes deposited between the bridge piece and one contact of said set.

In the accompanying drawing, which illustrates the preferred form of my invention, I have shown my improved switch as being used for controlling the circuit of an electricallyoperated fuel pump, but I wish it to be understood that it is capable of various uses. Said switch comprises a bridge piece I, preferably of annular form and arranged so that it is capable of revolving, and two sets of contacts J and K, each of which sets comprises a plurality of contacts, arranged at opposite sides of the gap in the circuit across which the bridge pieceI extends. of silver or some other suitable material that is a good electrical conductor, and is rigidly connected to a disk-shaped insulator that is mounted on the outer end portion of a switch operating member G in such a way that said bridge piece is capable of revolving freely on the member G and isalso capable of a slight rocking movement relatively to said member G. I have not illustrated the means that is used to-actuate the operating member G, as various means may be used for this purpose.- Suffice it to say that when the apparatus with which the switch is used is in normal operation, the operating member G will move longitudinally, first in one direction, so as to close the circuit controlled by the switch, and then in the opposite direction so as to open said circuit. When the switch is used to automatically open and close the 100 The bridge piece I is preferably formed:

hole through which the outer end portion of the switch operating member G projects.

In the form of my invention herein illustrated the insulator that carries the bridge piece I is rotatably mounted in an annular groove 8 in the switch operating member G, the width of said groove being a trifle greater than the thickness of said insulator, thereby permitting said insulator to rock relatively to the switch operating member G under certain conditions, as hereinafter described. The set of contacts J, which I will refer to as the stationary contacts, are connected to a plate 9 formed of brass or some other suitable electrical conducting material, which plate 9 is sustained by the supporting plate L and insulated from the same by an insulator 10, as shown in Figure 2. Any suitable means may be used for establishing electrical connection between the plate 9 carrying the contacts J and the circuit which the switch controls, the means herein illustrated for this purpose consisting of a substantially U-shaped spring 11 formed of electrical conducting material which has one of its legs connected by rivets 12 to the plate 9 and its other leg arranged so that it bears against a terminal 13 forming part of the circuit controlled by the switch, the spring 11 being insulated from the supporting plate L by means of an insulator 14. The other set of contacts, which I will refer to as the movable contacts, are mounted on a shiftable or movable plate 15' formed of brass or other suitable electrical conducting material and grounded in any suitable way, as,

for example, by being arranged in metallic contact with the supporting plate L, which, as previously stated, is formed of magnetic material. The plate 15 which carries the movable contacts K is arranged diametrically opposite the plate 9 that carries the stationary contacts .J', as

shown in Figure 1, and said movable plate 15 is mounted sothat it is capable of rockingon its longitudinal axis. One convenient method of mounting the plate 15 is to provide it with three longitudinally-aligned holes located at the longitudinal center of same, the end holes being adapted to receive balls 16 which are interposed between said plate and the supporting member L, and the center hole being adapted to receive a ball 17, which is arranged between the top side of the plate 15 and a clamping'bar 17 that is attached to the supporting member L and which is maintained under a slight tension so as to hold the plate '15 in tight engagement vious, however, that the plate 15 which carries the movable contacts could be mounted in various other ways without departing. from the spirit of my invention,

When the switch operating member G is at the endv of its stroke. in one direction, the bridge piece I is held in engagement with the two sets of contacts J and K, usually by the action of a spring (not shown) which exerts pressure on the operating member G, thereby causing the circuit to be maintained in its closed condition.

When said switch-operating member G moves in the opposite direction, the bridge piece I separates from the contacts J and K, and thus opens said circuit, the above operations being repeated automatically, with the result that the switch will intermittently open and close the circuit. In the event particles of dirt or other foreign matter lodge between the bridge piece I and the contacts J and K, said particles will not remain long at their point of lodgrnent, due to the-fact that the vibrations of the apparatus on which the switch is mounted, produces sumcient relative movement between the said bridge piece and contacts to remove or knock off any foreign particles on said elements. Moreover, as the switch comprises at least two contacts on each side of the gap in the circuit, and a bridge piece that laps over or is arranged in opposed relationship to all of said contacts, a plurality of paths for the electric current are provided acrossthe gap in the circuit, thereby making the switch reliable in operation and practically eliminating the possibility of its failing to carry the current across the gap, as so often occurs in switches or" conventional design when dirt or other foreign matter becomes deposited between the bridge piece and either one of the single contacts at opposite sides of the gap in the circuit. In other words, a switch of the construction above described will function properly, even though foreign matter collects between the bridge piece and one contact arranged at each side of the gap in the circuit, due to the fact that there is another path or other paths for the current to travel across the gap. 110 In the event a particle of foreign matter becomes deposited between one of the stationary contacts J and the bridge piece I, said bridge piece will rock relatively to the switch operating member G sufficiently to accommodate said piece of foreign matter, as shown in Figure 2, and thus permit the bridge piece to engage or bear upon the other stationary contact. Likewise, if a piece of foreign matter becomes deposited between the bridge piece and one of the movable contacts K, the plate 15 that carries the movable contacts will rock or assume an inclined position, as shown in Figure 3, and thus cause the other contact of the movable set to bear against the bridge piece I and provide a path for the electric current. It is immaterial how many contacts are used to form the two sets of contacts at opposite sides of the gap in'the circuit, but I have found that if the switch is provided with four contacts arranged in pairs at opposite sides of the gap, and that if said contacts and the bridge piece with which they co-operate are mounted in the manner previously described, I obtain a three-point bearing for the bridge piece on the contacts, which insures the proper engagement between said elements under practically all operating conditions, the relative movement between the bridge piece andconta-cts not only tending to cause any particles of foreign matter to be knocked off, but also insuring the bridge piece I ooacting properly with at least one contact of each set of contacts, in the event foreign particles adhere to one contact of each set.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An automatically-operating switch for intermittently opening and closing an energizing circuit, comprising a bridge piece and sets of contacts, each comprising a plurality of contacts, arranged at opposite sides of the gap in the circuit and adapted to co-act with said bridge piece, and a shiftable or movable member that carries the set of contacts arranged at one side of the gap.

2. An automatically-operating switch for intermittently opening and closing an energizing circuit, comprising a bridge piece and sets of contacts, each comprising a plurality of contacts, arranged at opposite sides of the gap in the circuit and adapted to co-act with said bridge piece, said bridge piece being mounted on the member which carries same in such a Way that it is capable of rocking slightly relatively to said member, and a shiftable or movable member that carries the set of contacts arranged at one side of the gap.

3. An automatically-operatingswitch for intermittently opening and closing an energizing circuit, comprising a circular bridge piece and sets of contacts with which said bridge piece coacts, arranged at opposite sides of the gap of the circuit and each comprising a plurality of contacts, said bridge piece being rotatably mounted.

4. An automatically-operating switch for intermittently opening and closing an energizing circuit, comprising a revoluble bridge piece and sets of contacts with which said bridge piece coacts, arranged at opposite sides of the gap of the circuit and each comprising a plurality of contacts, and a rockable member'that carries the set of contacts arranged at one side of the gap.

5. An automatically-operating switch for intermittently opening and closing an energizing circuit, comprising a revoluble bridge piece and sets of contacts with which said bridge piece coacts, arranged at opposite sides of the gap of the circuit and each comprising a plurality of contacts, said bridge piece being capable of a slight rocking movement relatively to the part on which it is mounted, and a rockable member that carries the set of contacts arranged at one side of the gap.

' WILLIAM C. CARTER. 

